Flow diversion devices, such as the Pipeline embolization device, the Surpass flow diverter, and the Silk flow diverter, are stent-like devices composed of tightly-braided, thin wire elements typically used for the treatment of intracranial aneurysms. These devices are employed endovascularly to treat aneurysms by diverting blood flow away from the aneurysm to induce aneurysm thrombosis, which helps prevent rupture of the aneurysm and may eventually result in the gradual shrinkage and occlusion of the aneurysm. In addition, when used for fusiform aneurysms (i.e., aneurysms with no definable neck), the flow diversion device may promote reconstruction of a smooth endothelial covered channel in continuation with the parent artery. While the flow diversion device directs blood away from the aneurysm, the thin-wire braided design allows modest through-flow of blood to maintain the patency of important small arterial side branches adjacent to the treated aneurysm.
Large intracranial aneurysms (which range in diameter from 10-25 mm) and particularly giant intracranial aneurysms (those greater than 25 mm in diameter) frequently have a wide-neck (dome-to-neck diameter ratio of less than 2) or are fusiform. Typically, large and giant aneurysms have poor occlusion, rupture and survival rates regardless of the form of therapy (e.g., open brain surgery or other endovascular techniques) used to treat them. The use of finely braided stent devices to divert blood flow away from aneurysms has yielded promising treatment results compared to open surgery and other conventional endovascular techniques, such as coil embolization with or without the assistance of an endovascular stent or balloon remodeling.